Boiling Point Of Water At Altitude Calculator

Use our boiling point of water at altitude calculator to quickly determine the temperature at which water boils at various elevations above sea level. Understand the science behind it and get accurate results instantly.

Calculator

Boiling Point at Various Altitudes

Altitude (m)	Altitude (ft)	Pressure (kPa)	Boiling Point (°C)	Boiling Point (°F)
0	0	101.325	100.0	212.0
500	1640	95.46	98.5	209.3
1000	3281	89.88	96.9	206.5
1500	4921	84.56	95.4	203.7
2000	6562	79.50	93.8	200.8
3000	9842	70.12	90.7	195.2
5000	16404	54.05	83.9	183.0
8848	29029	31.43	70.8	159.4

Table illustrating the boiling point of water at different altitudes, from sea level to the summit of Mt. Everest.

What is the Boiling Point of Water at Altitude Calculator?

The boiling point of water at altitude calculator is a tool used to determine the temperature at which water boils at a specific elevation above or below sea level. As altitude increases, atmospheric pressure decreases, and this lower pressure causes water to boil at a lower temperature than the standard 100°C (212°F) at sea level.

This calculator is useful for mountaineers, pilots, cooks at high altitudes, and scientists. Anyone who needs to boil water or cook food at elevations significantly different from sea level will find this tool helpful because cooking times and methods may need adjustment. For example, foods take longer to cook at higher altitudes because water boils at a lower temperature. The boiling point of water at altitude calculator provides the exact boiling temperature for a given altitude.

A common misconception is that water always boils at 100°C. This is only true at standard sea-level atmospheric pressure. The boiling point of water at altitude calculator demonstrates how this temperature changes with elevation.

Boiling Point of Water at Altitude Formula and Mathematical Explanation

The boiling point of a liquid is the temperature at which its vapor pressure equals the surrounding atmospheric pressure. At higher altitudes, the atmospheric pressure is lower, so the vapor pressure required for boiling is reached at a lower temperature.

1. Atmospheric Pressure at Altitude (P): A common approximation for pressure (P) in Pascals at an altitude (h) in meters is given by the barometric formula, simplified for the troposphere (up to about 11 km):
`P = P0 * (1 – L * h / T0)^(g * M / (R * L))`
Where `P0` = 101325 Pa (sea-level pressure), `L` = 0.0065 K/m (standard lapse rate), `T0` = 288.15 K (sea-level temperature), `g` = 9.80665 m/s², `M` = 0.0289644 kg/mol (molar mass of dry air), `R` = 8.31447 J/(mol·K).
A good approximation up to 11km is: `P = 101325 * (1 – 2.25577E-5 * h)^5.25588`

2. Boiling Point from Pressure (T_b): We can use the Clausius-Clapeyron relation, often expressed via the Antoine equation, rearranged to solve for temperature (T_b in °C) given pressure (P in Pascals):
`T_b = (B / (A – log10(P / 133.322))) – C`
Where A=8.07131, B=1730.63, C=233.426 are Antoine coefficients for water (with P converted to mmHg by dividing by 133.322).

The boiling point of water at altitude calculator uses these relationships to find the boiling point for your input altitude.

Variables Used

Variable	Meaning	Unit	Typical Range (Example)
h	Altitude above sea level	meters (m)	-400 to 30000 m
P	Atmospheric pressure	Pascals (Pa), kPa, atm	~30,000 to 105,000 Pa
P0	Standard sea-level pressure	Pascals (Pa)	101325 Pa
T_b	Boiling point temperature	°C, °F	~70°C to 101°C
A, B, C	Antoine equation coefficients	Dimensionless/various	Specific to water

Practical Examples (Real-World Use Cases)

Understanding how altitude affects boiling point is crucial in various scenarios.

Example 1: Cooking in Denver

Denver, Colorado, is approximately 1609 meters (5280 feet) above sea level. Using the boiling point of water at altitude calculator with an altitude of 1609 m:

• Altitude: 1609 m
• Calculated Atmospheric Pressure: ~83.4 kPa
• Calculated Boiling Point: ~94.8 °C (202.6 °F)

In Denver, water boils almost 5.2°C lower than at sea level. This means foods like pasta or eggs will take longer to cook, and recipes might need adjustment.

Example 2: Mountaineering on Mount Everest Base Camp

Mount Everest South Base Camp is around 5364 meters (17598 feet). Using the boiling point of water at altitude calculator:

• Altitude: 5364 m
• Calculated Atmospheric Pressure: ~51.9 kPa
• Calculated Boiling Point: ~82.7 °C (180.9 °F)

At Base Camp, water boils at a much lower temperature, significantly increasing cooking times and affecting the preparation of hot drinks and dehydrated meals. Pressure cookers are often used at such altitudes to raise the boiling point and cook food more efficiently. Our pressure cooking time calculator can be helpful here.

How to Use This Boiling Point of Water at Altitude Calculator

Using the boiling point of water at altitude calculator is straightforward:

1. Enter Altitude: Input the altitude for which you want to find the boiling point into the “Altitude” field.
2. Select Unit: Choose the unit of your entered altitude (meters, feet, kilometers, or miles) from the dropdown menu.
3. View Results: The calculator will automatically update and display the boiling point in both Celsius and Fahrenheit, along with the calculated atmospheric pressure at that altitude.
4. Reset: Click the “Reset” button to return the altitude to 0 meters (sea level).
5. Copy Results: Click “Copy Results” to copy the altitude, pressure, and boiling points to your clipboard.

The results from the boiling point of water at altitude calculator can help you adjust cooking times or understand scientific principles related to altitude and pressure. For instance, if you’re baking at high altitude, you might need to adjust your recipe based on the lower boiling point; see our high-altitude baking guide.

Key Factors That Affect Boiling Point Results

Several factors influence the boiling point of water, with altitude (and thus atmospheric pressure) being the most significant when using the boiling point of water at altitude calculator.

• Altitude: The primary factor. As altitude increases, atmospheric pressure decreases, lowering the boiling point. The boiling point of water at altitude calculator is designed specifically to account for this.
• Atmospheric Pressure: Directly related to altitude. Lower pressure means a lower boiling point. Weather systems can cause slight variations in local pressure even at the same altitude, but the calculator uses a standard atmospheric model. You might also find our barometric pressure converter useful.
• Purity of Water: The presence of solutes (like salt or sugar) in water increases its boiling point. This phenomenon is called boiling point elevation. The calculator assumes pure water (H2O). For cooking, the effect of dissolved solids is usually small but present.
• Local Gravity Variations: Although very minor, local gravity can slightly affect atmospheric pressure distribution, but this is negligible for most practical purposes compared to the effect of altitude.
• Humidity: High humidity can slightly lower the density of air and thus marginally affect pressure, but this effect is very small on the boiling point compared to altitude changes. The standard model used by the boiling point of water at altitude calculator assumes dry air for pressure calculation.
• Enclosed Spaces/Pressure Cookers: If water is boiled in a sealed container like a pressure cooker, the pressure inside increases, significantly raising the boiling point. This is the opposite effect of high altitude and is not directly handled by this specific calculator, which assumes open-air boiling. Our ideal gas law calculator can explore pressure-temperature relationships.

Frequently Asked Questions (FAQ)

What is the boiling point of water at sea level?

At standard sea-level pressure (101.325 kPa), pure water boils at 100°C (212°F). You can verify this with the boiling point of water at altitude calculator by setting the altitude to 0.

Why does water boil at a lower temperature at high altitudes?

At higher altitudes, the air pressure is lower. Boiling occurs when the vapor pressure of water equals the surrounding air pressure. Since the air pressure is lower, less vapor pressure (and thus a lower temperature) is needed for water to boil.

How much does the boiling point decrease with altitude?

The boiling point decreases by approximately 0.9 to 1.1°C for every 300 meters (or about 1°F per 500 feet) increase in altitude, although the rate of decrease is not perfectly linear. The boiling point of water at altitude calculator uses a more precise formula.

Does the boiling point of water change inside a pressure cooker at high altitude?

Yes, but a pressure cooker artificially increases the pressure inside the pot, raising the boiling point of water above what it would be in an open pot at that altitude, and often above 100°C.

Can I use this calculator for altitudes below sea level?

Yes, the boiling point of water at altitude calculator can accept negative altitude values (e.g., for areas like the Dead Sea) and will show a boiling point slightly above 100°C.

How does this affect cooking?

At higher altitudes, because water boils at a lower temperature, foods cooked by boiling or steaming (like pasta, rice, vegetables, and eggs) will cook more slowly. You may need to increase cooking times. Baking is also affected; see our baking conversion guide.

Is the calculator accurate for all altitudes?

The calculator uses standard atmospheric models and the Antoine equation, which are very accurate for most habitable altitudes and up to about 11,000 meters. For extreme altitudes beyond the troposphere, the pressure model would need adjustment, but boiling water is less common there.

What if the water isn’t pure?

Dissolving substances like salt or sugar in water will raise its boiling point (boiling point elevation). The boiling point of water at altitude calculator assumes pure water. The increase due to typical amounts of salt in cooking is usually small (less than 1°C).